1. Field of the Invention
The present invention relates to a cooling system, a method, and an apparatus for liquid cooling an article of computer equipment.
2. Background Art
Computer equipment is generally assembled within an enclosure or to an open rack. Computer components, such as server blades, power supplies, switches and data storage modules, may be added or removed at will by a user to provide scalability for the system and field replacement of circuit components.
Computer components generally require cooling to operate at peak efficiency. Cooling for computer components is normally provided by circulating air that is driven by fans that circulate around the computer components. The air is then cooled by flowing through heat exchangers that are disposed adjacent to the computer components. Alternatively, the air circulating through the computer components may be cooled by the air conditioning system of a data center. As the number of computer components provided in electronics enclosures or racks increases, problems relating to cooling the components also increases. The cost of cooling a high-performance computing center increases the cost of operating the computing center.
Computer components are normally housed in enclosures have fans that blow air over hot circuits and then into the computer room or into an air-to-liquid heat exchanger. This approach creates a multi-step air-to-water-to-refrigerant cycle for expelling heat from the enclosure. Energy conversion inefficiencies are compounded by the use of air flow fans, heat exchanger grids and compressors. Air flow fans used to circulate air also consume power and generate additional heat that must be removed from the system.
High pressure liquid cooling systems have been developed in which high pressure water, for example water at 40 to 50 psi, may be pumped through a closed manifold including tubes and heat exchanger fins that are located adjacent to the computer components that require cooling. Such high pressure systems may require air flow fans that move air across the electronic components to absorb heat. The air then flows through heat exchanger fins that absorb heat from the air. The heat transferred to the fins of the heat exchanger is then absorbed by the high pressure liquid in the tubing and taken to a suitable chiller or cooling system that removes the heat from the system. Other high pressure liquid cooling systems directly cool electronic components by circulating liquid through tubes or conduits without using an air heat exchange interface.
The cost of operating a high pressure liquid system may be substantial in a high performance computing environment. High performance computing environments may have numerous racks that each require various quantities of cooling capacity. For example, 64 components may be configured per rack that may require dissipation of as much as 50,000 watts of heat into the computer environment per rack. Cooling such a large number of computer components consumes power for cooling the components on the racks and adds to the total cost of operating the data center.
Pressurized liquid cooling systems for electronics enclosures are subject to pressure variations. Adding and removing modules from the system may affect the head pressure or flow of water through the system. Pressurized systems are subject to variation due to pump performance, electrical control variations, and pressure variations caused by adding or removing components from the system. Higher pressure systems may stress liquid connections and be more prone to development of leaks. Higher cost components of a high pressure cooling circuit increase the cost of the cooling system.
The method and apparatus summarized and described below is directed to solving the above problems.